The present invention relates to an acetabular cup inserting instrument which is used by a surgeon to insert and properly position an acetabular cup implant into its proper anatomic location.
A wide variety of instruments are known in the art for inserting acetabular cup implants into position in the acetabulum. Many such insertion instruments include a first handle with a second handle extending therefrom to assist in the insertion procedure. Typically, the second handle is in a fixed orientation relative to the first handle. Examples of such acetabular instruments are disclosed in the following U.S. Pats. Nos. 4,528,980 to Kenna; U.S. Pat. No. 4,475,549 to Oh; U.S. Pat. No. 4,305,394 to Bertuch, Jr.; and U.S. Pat. No. 3,859,992 to Amstutz. Once the acetabular cup is attached to such instruments, the handles are in a fixed orientation with regard to the cup. With certain cup designs a particular orientation of the cup may be desirable to achieve proper anatomic positioning. An example of such a cup design is a cup which has pegs protruding from the outer surface, such as the pegged cup disclosed in U.S. Pat. No. 3,781,918 to Mathys or the BIAS Acetabular Cup Component sold by Zimmer, Inc. Accordingly, when the first and second handles are both in a permanently fixed orientation with regard to the cup, it may result in the second handle being in an awkward or inconvenient position in order to insert the cup in the desired orientation. Also, if the first handle needs to be rotated about its axis during the insertion of the cup or the removal of the insertion instrument from the cup, a fixed secondary handle may be awkward or get in the way.